Safety device for punching presses



J. A. VAN HORN.

SAFETY DEVICE FOR PUNCHING PRESSES.

APPLICATION FILED NOV. 24. 1920.

Patented Feb. 7, 1922.

2 SHEETS-SHEET I.

J. A. VAN HORN.

SAFETY DEVICE FOR PUNCHING PRESSES.

APPLICATION FILED NOV. 24. 1920.

1,405,466. Pdtented Feb. 7, 1922.

2 SHEETS-SHEET 2- 22 \A L g F .6 L r amour 0'0 UNITED STATES...

JOI-IN A. VAN HORN, OF SHELBY, OHIO.

j SAFETY nnvicn r03 rnivcnrivo rnns'sns. f

Specification of Letters l 'atent, v Patented F 1 7 1922,

Application filed November 24, 1920. Serial No. 426,232. v

' To all whom it may cancer-mi Be it known that I, J OHN A. VAN HORN,

a citizen of the ,United States of America, residing at Shelby, in the county of Richland and State of Ohio, have invented certain new and useful Improvements in a Safety Device for Punching Presses, of which the following is a specification.

- It is well known to those skilled in the art of operating punching presses, or ma chines with cooperating pressure elements, one or both being movable toward the other, that in placing or feeding the work between the pressure elements that the operator is in danger of beinginjured by the elements, and also in the'event of theoperator notremoving the hands, fingers or other part of the body from between the pressure elements before the pressure elements are in such close proximity to each other as to injure the operator.

The machines to which the present inventionis applied are constructed and adapted to be put in operation by the actuation of a treadle or the like, but are often inadvert: ently operated without warning or any act of the operator, I

The primary object, therefore, of the present invention isto provide means for swinging safety arms or equivalent members from and to a position between the pressure elements and an arm or the like from and to a position in close proximity thereto, at a predetermined time after the treadle or the like is actuated to operate the machine and further to provide automatic means for swinging said safety arms or equivalent members in a similar manner in the event of the machine being inadvertently operated without the act of the operator. 7 i

A furtherobject is to provide meansfor supporting adjusting and spacing a plurality of safety arms or like members in such a manner with respect to each other so as to provide a guide for the operator in feeding the work between or removing it from between'the pressure elements thereby forcing the operator to place his hands be tween the element in the same position at all times. I j j A further object'is to provide means of varying the throw or swing of the arms or equivalent members.

The preferable means employed in applying the invention consists in swinging safety arms or the like in andout the path of and adjacent to the cooperating pressure elements at a predetermined time. When. the machine is in operation, said safety members or arms being adapted to contact with and eject the fingers, hands or other foreign ob: struction from between the elements, and

forcing and pushing thefingers'or other ob the ,a e a r the device taken on the line B''-B 'of'Figl Fig. 5, is a sectional plan viewof taken on the line I g H J Fig. 6, is a detail sectional side elevati of the device" taken'on th lj g o ig. 1;

In the drawlngs reference numerals"1'1 represent the frame-work of conventional type of punching'press or the like to which the invention is preferablyiapplied to show its construction and operation, 2 the eccen- I trio shaft and 3 the press. 1 j a Supporting brackets 14 and;5 are secured to the frame-work in spaced apart relation bythe capscrews 6.' Bearing members? and 8 are mounted upon the'brackets l and 5 and adjustably heldand secured thereto by the reciprocating head of the cap screws 9. as shown clearly in Fig. Q.

A shaft 10 is journaled for rotation in suit able bearings formed in the members Tand 8. The shaft 10 is journaled in the bea'rings so as to leave both ends thereof projecting beyond the bearings and .8. :A cr'ank 11 which is providedwith a slot 12 isfsecured by a pin 13 or a set screw 14: on thejprojecting endof the shaft, that extends beyond the bearing 8. The crank, 11' positioned upon the shaft so as to extendinwardlyfor'towar d the front of thepress at anypre-[determined angle desired withrespect to th Plane of the bed 15 of the press. A crank 16 similar to the crank 11 is rigidly secured t0- the end of the shaft 10 that projects beyond the bearing member, 7. The crank 1:6,is pro. vided with a crank pin 17.

The preferred @Qnstruction and 31361 j ustably clamping the clamps to the horizon tally arranged shaft 10 and to adjustably clamp and support the vertical portions 20 of safety arms 21.

The horizontal portions 22 of the safety armsare preferably positioned and spaced apart from each other as shown in Fig. 2, to, guide the operator in feeding the work to and from between the die and punch or pressure elements and to force thehands and fingers of the operator in feeding the work i to and from the die to assume positions that will force the safety arms to strike, the bottom and top of the hands or fingers of the operator, thereby doubly insuring the ejection or removal of the hands and fingers from'the danger zone.

To provide for the operation of the safety arms or the like simultaneously with operation of the treadle 23 of the'treadle mechanism, a chain 241 is pivotally connected to a stud bolt crank pin 25 which is adjustable in the slot 12, and the opposite end of the chain is pivotally connected to and adjustable on the treadle connecting rod 27.

The manual operation of the safety device if is asfollowsz-Th operator imparts, "a

ments and adjacent to the die or work and the other positioned in a plane below the die and spaced apart from the first mentioned arm. One of the arms is preferably positioned in close proximity to the front of the die. The actuation of the treadle forces the safety arms or the like to oscillate or swing to the dotted line positions shown in Fig: 3, thereby striking, pushing and ejecting any obstruction from between the pressure elements or in the path of travel or throw of the safety arms'i. e.,the fingers or hands of the operator." The safety means-can be adjusted through the medium of the crank connection and safety arms with respect to their prek ferrednormal idling positions.

To provide against the liability of injury to the operator on account of the rotation of theeccentric shaft and downward stroke of the head attached thereto when such shaft operates without any act or manipulation of safety device is follows A crank pin 28 is secured. to the eccentric shaft anda connecting rod 29 is pivotally connected thereto. The opposite end of the connecting rod 29 is provided with an adjustable member 80 having a slot 31 formed therein adjacent to its end to receive the crank pin 17.

The crank 16 is positioned on the shaft 10 so as to permit the crank 1'7 to contact with the upper wall of the slot, when the eccentric shaft 2 is in its normal idling position as shown in Figs. 1 and 3. The crank pin 17 is held, maintained and supported under tension against the upper wall of the slot 31 by the expansible spring 32 which is attached to .the crank 16 and the clamp 33 which is adjustably secured to the connecting rod 29. If for any reason theeccentric shaft is ro tated the upper wall of the slot will be automatically forced by the mechanism connected to the eccentric shaft to exert a pressure upon the crank pin 17 and crank 16 which will partially rotate the shaft .10, which in turn moves or swings the safety armsor the like to the dot-ted line positions shown in Fig. 3, in the same manner as when actuated by the operation of the treadle mechanism.

If the operator prefers to use a different or modified type of safety member or arms with or without either or both of the arms hereinbefore described, a yoke shaped member 34 can be used which consists of the bars 35 and provided and constructed as 36. An additional frictional clamp 37 is used 7 with the modified form of safety member. A soft yielding material 88 forms the end. portion of the yoke 34. The advantage of using soft material for-the end portion of yoke 34 instead of another metallic arm, consists in preventing injury to the die or punch, in the eventthat the operator has not properly adjusted and timed the swing of the arms to swing out of the path of the movable pressure elements at a predetermined time.

It will be observed that in the event of wrong timing of the parts no injury would be done to the die or punch, even though the part 38 should be subjected to the pressure of the elements as the material 38 is made of soft and pliable material.

Attention is called tothe fact that the safety arms can be adjusted and s aced apart vertically, laterally and angularlywith respect to each other which in connection with the means for changing the swing or throw of the arms provides facilities for the use of the device with different kinds of dies; 01' punches and affords facilities for adjustment to meet the requirements of vdifferent sizes of operators hands.

It will be noted that the same safety mechanism is operated automatically with out any act of the operator that is operated by the manual act of the operator when the treadle is operated.

Material changes and alterations can be made without departing from the principle of the invention herein described; hence it is not intended to limit same to the specific structure shown and described.

I claim:

1. In a safety device for presses, a rotatable shaft mounted on the frame of the press, guards mounted upon the rotatable shaft which are adjustable vertically, horizontally and radially with respect to each other, and means to impart a to and fro movement to the guards toward the operator when actuated by the treadle.

2. A safety device for presses, including a guard member normally positioned between the pressure members of the press, a

second guard member normally positioned front of one of said pressure members, and means for simultaneously operating sa1d guard members.

4. A safety device for presses, including independent guard members having distinctive protective areas, an operatingmember,

and means for independently and adjustably connecting the guard members to said operating member.---

In testimony whereof I affix my signature.

' JOHN A. VAN HORN. 

